San Marcos weather in May

In May, San Marcos sees average daytime highs of 32°C and overnight lows near 25°C, with 310 mm of rain across 29.3 wet days and about 12.4 hours of daylight. It is the 5th-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 32°C through the month. The sky is clear or mostly clear about 1% of the time in May, and the air most often feels miserable.

Daylight stretches from about 12 h 18 min at the start of May to 12 h 30 min by month's end. Set against the rest of the year, May is San Marcos's 12th-clearest and 11th-windiest month. For the whole year in context, see San Marcos's year-round climate.

Daytime high
32°
5th warmest
Overnight low
25°
9th coldest
Rainfall
310 mm
29.3 wet days
Daylight
12 h 24 min
5:45 AM – 6:09 PM
Cloud cover
92%
12th clearest
Wind
5 km/h
11th windiest
Solar energy
4.63 kWh/m²
Travel score
2.1
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 32°C through the month.

A typical May day in San Marcos reaches about 32°C in the afternoon and slips back to 25°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 34°C. Set against its neighbours, May runs about 1°C cooler than April and on par with June.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13225
23225
33225
43225
53225
63225
73225
83225
93225
103225
113225
123225
133225
143225
153225
163225
173225
183225
193225
203225
213225
223225
233225
243225
253225
263225
273225
283225
293225
303225
313225

How May really feels in San Marcos

Once humidity and wind are folded in, May averages 31 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
31
31 feel dangerously hot (≥ 39°C)
Days feeling ≤ C
0
wind chill below the day's low

The story in May is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

San Marcos weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan33° / 24°317.811.63.8
Feb35° / 25°316.911.72.9
Mar35° / 26°8015.211.92.3
Apr33° / 25°19825.712.22.1
May32° / 25°31029.312.42.1
Jun32° / 25°26027.112.52.2
Jul32° / 25°24427.312.52.3
Aug32° / 24°25828.312.32.2
Sep32° / 24°26528.912.12.2
Oct31° / 24°27329.811.82.3
Nov31° / 24°19627.211.62.5
Dec32° / 24°9618.811.53.3

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 1% of the time in May, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 4% of May, with mostly cloudy or overcast conditions the remaining 95%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1496
2496
3397
4397
5397
6496
7496
8496
9496
10496
11496
12496
13595
14595
15595
16595
17595
18595
19595
20595
21595
22595
23595
24595
25595
26595
27694
28694
29694
30694
31694

Chance of precipitation in May

Any precipitation

San Marcos gets around 310 mm of rain over 29.3 wet days in May, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 94% and peaks near 95% on the wettest days.

0%20%40%60%80%100%151015202531
Rain chance (%)
194
294
395
495
595
695
795
895
995
1095
1194
1294
1394
1494
1594
1694
1794
1894
1994
2094
2194
2294
2394
2494
2594
2694
2794
2894
2994
3094
3194

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the miserable band about 94% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Oppressive (%)Miserable (%)
1892
2892
3793
4793
5694
6694
7694
8694
9595
10595
11595
12595
13595
14595
15595
16595
17595
18595
19595
20694
21694
22694
23694
24793
25793
26793
27793
28793
29793
30694
31694

Wind in May

Winds average 5 km/h in May.

Across May, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 18 min at the start of May to 12 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 12 minutes over May. Sunrise moves from 5:49 AM to 5:44 AM, and sunset from 6:07 PM to 6:12 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:496:07
212.35:486:07
312.35:486:07
412.35:486:07
512.35:476:07
612.35:476:07
712.35:476:07
812.35:476:07
912.45:466:08
1012.45:466:08
1112.45:466:08
1212.45:466:08
1312.45:456:08
1412.45:456:08
1512.45:456:08
1612.45:456:09
1712.45:456:09
1812.45:456:09
1912.45:456:09
2012.45:446:09
2112.45:446:10
2212.45:446:10
2312.45:446:10
2412.45:446:10
2512.45:446:10
2612.45:446:11
2712.45:446:11
2812.55:446:11
2912.55:446:11
3012.55:446:12
3112.55:446:12

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.63 kWh/m².

For context, solar energy here swings from a low near 4.41 kWh/m² to a high of 5.7 kWh/m² in March across the year — May's 4.63 kWh/m² sits near the bottom.

024151015202531
Solar energy (kWh/m²)Level
14.7Bright
24.7Bright
34.7Bright
44.7Bright
54.7Bright
64.7Bright
74.7Bright
84.7Bright
94.7Bright
104.7Bright
114.7Bright
124.7Bright
134.6Bright
144.6Bright
154.6Bright
164.6Bright
174.6Bright
184.6Bright
194.6Bright
204.6Bright
214.6Bright
224.6Bright
234.6Bright
244.6Bright
254.7Bright
264.7Bright
274.7Bright
284.7Bright
294.7Bright
304.7Bright
314.7Bright
Planning a trip in May

Is May a good time to visit San Marcos?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

2.1
Sightseeing
11th-best month of the year
3.5
Beach & pool
11th-best month of the year

May is a weaker month for outdoor sightseeing in San Marcos.

What to pack for San Marcos in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, San Marcos sees daytime highs around 32°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 29 days see rain.

light clothesrain gearsun protection

UV index in San Marcos in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Marcos peaks around June 15 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 10 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highJun 15UV 13Dec 13UV 10
UV index (midday)Level
Jan11Extreme
Feb12Extreme
Mar12Extreme
Apr12Extreme
May12Extreme
Jun13Extreme
Jul12Extreme
Aug12Extreme
Sep12Extreme
Oct12Extreme
Nov10Very high
Dec10Very high

Air quality in San Marcos in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in San Marcos is worst in March — around 34 µg/m³ PM2.5 (moderate), about 2.7× the cleanest month (November, 12 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 1933 µg/m³Nov 1812 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb21Moderate
Mar34Moderate
Apr27Moderate
May22Moderate
Jun20Moderate
Jul20Moderate
Aug17Moderate
Sep14Moderate
Oct13Moderate
Nov12Moderate
Dec13Moderate
Location & terrain

Where is San Marcos?

San Marcos sits at 8.7°N, 75.1°W, 25 m above sea level, in Colombia. The nearest listed city is San Benito Abad, 32 km away.

Topography around San Marcos

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Marcos.

Within 3 km, the terrain around San Marcos has only modest variations in elevation — a maximum elevation change of 18 m around an average of 22 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 73 m; within 80 km, large variations in elevation — a maximum elevation change of 1,004 m.

The land around San Marcos is covered by grassland (57%) within 3 km, grassland (69%) within 16 km, and grassland (68%) within 80 km.

3 km
18 m
16 km
73 m
80 km
1,004 m
treesgrasslandcroplandartificial surfaceswaterwetland
May weather nearby: San Benito Abad 32 km · Ayapel 38 km · Sahagún 47 km · Sucre 48 km · Galeras 56 km · Planeta Rica 57 km · Chinú 58 km · Ciénaga de Oro 59 km

Colombia travel facts

Travel advisory
Level 3
Reconsider Travel
Power plugs
Type A / B
120 / 240 V · 60 Hz
Prices
≈ 38% of US
price level, 2025
GDP per capita
$8,562
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
74%
of population, 2024
Homicide rate
24.9
per 100k, 2023
Road deaths
15.4
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 480
Religion
Roman Catholic 64%Protestant 17%none 14%atheist 1%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Marcos (8.6597°, -75.1281°, elevation 25 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).